忽略Javascript正则表达式模式中的空格？ [英] Ignoring whitespace in Javascript regular expression patterns?

问题描述

根据我的研究，看起来Javascript的正则表达式没有任何内置等效于Perl的/ x修饰符或.NET的RegexOptions.IgnorePatternWhitespace修饰符。这些非常有用，因为它们可以使复杂的正则表达式更容易阅读。首先，我错过了什么，是否有一个内置的Javascript相当于这些？其次，如果没有，有没有人知道一个好的jQuery插件将实现这个功能？由于Javascript明显的正则表达式限制，将复杂的正则表达式压缩成一行是一种遗憾。

From my research it looks like Javascript's regular expressions don't have any built-in equivalent to Perl's /x modifier, or .NET's RegexOptions.IgnorePatternWhitespace modifier. These are very useful as they can make a complex regex much easier to read. Firstly, have I missed something and is there a Javascript built-in equivalent to these? Secondly, if there isn't, does anyone know of a good jQuery plugin that will implement this functionality? It's a shame to have to compress my complex regex into one line because of Javascript's apparent regex limitations.

推荐答案

如果我理解正确的话你想添加不属于正则表达式的空格吗？
据我所知，文字正则表达式是不可能的。

If I understand you correctly you want to add white space that isn't part of the regexp? As far as I know it isn't possible with literal regexp.

示例：

var a = /^[\d]+$/

您可以在以下几行中分解正则表达式：

You can break up the regexp in several lines like this:

var a = RegExp(
  "^" +
  "[\\d]+" +  // This is a comment
  "$" 
);

请注意，由于它现在是普通字符串，因此必须使用\\转义\

Notice that since it is now a normal string, you have to escape \ with \\

或者如果你有一个复杂的：

Or if you have a complex one:

var digit_8 = "[0-9]{8}";
var alpha_4 = "[A-Za-z]{4}";
var a = RegExp(
    digit_8 +
    alpha_4 + // Optional comment
    digit_8
 );

更新：使用临时数组连接正则表达式：

Update: Using a temporary array to concatenate the regular expression:

var digit_8 = "[0-9]{8}";
var alpha_4 = "[A-Za-z]{4}";
var a = RegExp([
    digit_8,
    alpha_4, // Optional comment
    digit_8,
    "[0-9A-F]" // Another comment to a string
 ].join(""));

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